1. Field of the Invention
The present invention relates to a linear measuring device, having a tape-shaped measuring body, a sensor/sensors, which is/are moved along the measuring body and in the course of this picks up/pick up the information stored on the measuring body, evaluates/evaluate it, if needed, and passes/pass it on.
2. Description of the Related Art
Linear measuring devices are employed in many areas, for example with measuring machines, machine tools, metal processing machines, laser installations, positioning installations, wood-working machines, automatic insertion machines, handling installations, welding installations, eroding installations, presses, lifting platforms, elevators and so on.
Moreover, such linear measuring devices have their areas of use in connection with position determinations on linear axes, linear motors and displacement units.
In many areas a particularly great measuring accuracy is demanded here, which extends down into the nanometer range.
Problems with the pick-up of measuring data can be caused, for example, by chips, spraying coolant fog, solvents, common oils, greases, water and mechanical wear.
Linear measuring devices of the type mentioned at the outset are known and documented in the catalog “Magnetisches Langenmesssystem MS01—Technisches Handbuch” (Magnetic Linear Measuring System MS01—Technical Manual) of Noesis GmbH. The measuring system employed in this connection includes a measuring body, a connector cable and an evaluation system, having a sensor head and an electronic evaluation device. The sensor head picks up the position while being moved over the measuring body. In the course of this, the sensor takes information from magnetic fields and passes these signals on to the electronic evaluation device. The electronic evaluation device processes these signals into interface-usable protocols for the exact position determination.
A problem with known linear measuring devices lies in that they cannot be replaced in case of repairs, if they are permanently integrated into the respective existing component or into the machine. To protect the measuring bodies against chips, spraying coolant fog, solvents, common oils, greases, water and mechanical wear, they are integrated into enclosed spaces, which cannot be opened for disassembly or reassembly without destroying them, i.e. the parts of the known linear measuring devices surrounding the space, in particular along the measuring axis, cannot be completely reused, or used without subsequent treatment.